Bill, The Repairsmith (Or, so we have problems with turrets? create a champ that can heal them!)

Heimerdinger used to passively repair turrets by standing next to them, there should be a dude who can help repair buildings like that. Maybe his passive is sorta like Zilean's where over time he gathers X amount of building repair and can channel it into a building to patch it up. His W could be Armor Forge, which drops an anvil and grants an armor shield to the first ally who runs over it.

His E could be Palisades, where he builds an destructable wall that absorbs X amount of damage before being destroyed. For his Q, something to do with a hammer, he probably smashes the ground and stuns or knocks up, something like that. I imagine his ult is he grants an AOE or a global shield that's either just a pure shield, or split between shield and an armor buff for x amount of seconds.

Honestly I just thought this champ up but thinking about him i'd love to play him, i wish he existed.